Wing sail

ABSTRACT

A handheld wing sail comprises a sailcloth supported on frame members. The frame members comprise two mast tubes positioned in a V shape defining a nose angle and opposite respective tips. A boom is located between the mast tubes, the boom being curved at the symmetry plane of the wing sail and connected to each mast tube by each supporting tubes, each fastened to the boom at one end by a connection member and fastened at the opposite end to the respective mast tubes. A traverse tube joins the mast tubes together and is fastened to the mast tubes by connection pieces. The mast tubes and the boom are connected to each other by a nose link, which comprises a threadlike connection member made of flexible but substantially non-stretchable material for making it possible to change the nose angle and to fold the mast tubes toward the boom, whereby to bring the wing sail into a folded position for turning the mast tubes and the boom freely in different directions when the wing sail is in the folded position and, thus, ready for transport. The tips of the mast tubes are at tips of the sailcloth and have flexible antenna portions for keeping the wing sail taut during sailing.

BACKGROUND OF THE INVENTION

The invention relates to a wing sail to be held by hand and intended forsailing on snow or ice and in suitable terrain conditions. Moreprecisely, the invention relates to a handheld wing sail to be usedpreferably for sailing on ice and snow, which wing sail comprises asailcloth or the like supported on frame portions, the frame portionscomprising two mast tubes positioned in a V shape and defining a noseangle between themselves, a boom located in the area between the masttubes and connected to each mast tube by means of supporting tubes,which are at one end fastened to the boom by means of a connectionmember and at the other end to the respective mast tubes by means ofconnection means, and a traverse tube joining the mast tubes togetherand fastened to the mast tubes by means of connection pieces.

The field of use of the wing sail according to the invention ispreferably other than water. The sail is preferably used when moving onice on skis or skates. Ice sailing by means of a wing sail and skis is anew demanding sport, making great technical demands on the wing sail. Onhard ice, for instance, speeds of 50 to 90 km/h can be achieved. Thewing sail must take a balanced driving position by itself and must notbegin to sway in an uncontrolled manner, for instance. The sailer shallhave an immediate and firm hold on the rig so that he "feels" itsmovements in his hands all the time and can coordinate the movements ofthe wing and his own movements according to the circumstances. Thismakes special demands on the structure and geometry of the rig.

An essential structural feature of known kite-like sailing rigs intendedfor sailboards and other light sailing equipments is a frame originallyplanned for sailing on water. Small rigs have been developed, in whichwind power can be used in the same way as set forth in U.S. Pat. No.3,487,800 relating to a sailboard rig, with the difference that kiterigs can be held also in the horizontal position during sailing. Oneobjective of kite rig constructions has been to achieve a controlledflight of sailboards by means of a symmetric, relatively small rigutilizing wind buoyancy, and accordingly, by means of a small sail area.

From Patent Application WO 87/03553 of Thomas A. Magruder and GermanOffenlegungsschrift 3 222 756 A1 of Georg Hamann are known wing-likesail constructions, which are fastened to a sailboard by means of amast. U.S. Pat. No. 4 382 417 of Harri Talve discloses a planarsymmetric wing construction to be mounted to rest on the mast of thecraft. From WO 90/13477 of Alan D. Ryon is known a symmetric rigconstruction also supported on the mast of the craft. A similar sailingequipment for sailing on snow or water skis is known from theApplication WO 86/00590 of Robert N. Keller. All five last-mentionedwing sail solutions require that they are supported on the craft by amast bearing their weight.

Symmetric sailing rigs to be held merely by hand are described forexample in European Patent Application 82108870 of James R. Drake andUlrich Stanciu, Published Application 0076954, and in Finnish PatentApplication 0823813 of Roland Claude Le Bail. Each hand-held wing-likesail construction known from the above-mentioned publications allows thewhole rig to sail soaring, having overcome its weight upon achieving asufficient speed. The sailing rig disclosed in European PublishedApplication 0076954 is suitable both for being mounted onto a mast andfor being held merely by hand. Since the boom of the last-mentioned rigis straight and the supporting tubes are positioned in the rear in sucha way that they are not suitable for being used as handles, sailingproperties and balance are not very good. In addition, the rig is noteasy to disassemble for transport. The sail construction according toFinnish Patent Application 823812 is not easy to disassemble fortransport. The long supporting tubes of the sail construction make thestructure heavy. Further, the tips of the sail construction are in useprone to breakage when they hit the ground, since they are stiff.

When sailing on ice or snow with above-mentioned known symmetrichand-adjustable kite rigs, which are inclineable to both sides of thehorizontal plane, for instance with sail constructions disclosed inFinnish Patent Application 823813, problems arise from the fact that therigs break easily when the wing tips thereof hit the ice, because iceconditions and high speeds strain the constructions, especially the wingtips.

On the one hand, wing sails operating on soaring principle shall be asaerodynamic as possible and therefore have narrow wing shapes, but onthe other hand, they shall have sufficient sail areas, because otherwisethey cannot be used in ordinary light wind conditions.

Generally, it can be said that known rigs comprise plenty of complicatedframe members tending to increase their weight and to make the foldingand transport difficult. The above holds true also for sailing rigs tobe held merely by hand.

SUMMARY OF THE INVENTION

Said problems and objectives have been solved by means of a wing sailaccording to the invention, which is characterized in that the masttubes and the boom are connected to each other by means of a nose link,which makes it possible to change the nose angle and to fold the masttubes in the boom direction for bringing the wing sail into a foldedposition, and that the free ends of the mast tubes comprise at tips ofthe sailcloth flexible antenna portions, to which are connectedtightening means for keeping the wing sail taut during sailing, and thatthe boom is curved in such a way that its maximum distance from thesailcloth is 25 to 50 cm at the symmetry plane of the wing sail and thatthe distance between the connection member and the nose link is 20 to50% of the boom length. The distance between the connection means of thesupporting tubes and the nose link is preferably 20 to 40% of the lengthof the mast tubes and the distance between the connection pieces and thenose link is 30 to 60% of the length of the mast tubes. The framemembers support the whole sailcloth evenly, and the antenna portionsmounted at the tips of the wing halves make an aerodynamically effectiveshape possible and prevent, due to their flexibility, the wing frombeing broken when the tip hits the ground. This facilitates thedismantling of the wing sail and improves the aerodynamic properties ofthe wing sail.

The whole frame of the wing sail according to the invention isimplemented by means of a weight-saving, self-stretching geometry, andan assembly of the equipment ready for use is facilitated by means of afolding nose link connecting the wing halves and protecting, thanks toits structure, the wing sail also against breakage. When the handles areat a sufficient distance from the sail, the wing sail is balanced andeasy to handle during driving. Preferred embodiments of the wing sailaccording to the invention are also set forth.

The greatest advantages of the wing sail according to the invention arethat it is extremely light, has a simple and durable structure, isfoldable, balanced and easy to manage, is safe and has good sailingproperties also in light wind conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the wing sail according to the invention and itsdetails are described through examples by means of the attached drawing,in which

FIG. 1 illustrates a wing sail and its user on skis sailing on snowyice,

FIG. 2 illustrates one embodiment of the wing sail mounted on the groundon its back, i.e. seen from below,

FIG. 3 shows the wing sail disassembled to a position ready fortransport,

FIG. 4 shows frame members of the wing sail and associated parts,

FIG. 5 shows one way of fastening a traverse tube and supporting tubesto a mast tube,

FIG. 6 shows one embodiment of the tip of the wing sail of FIG. 2, inwhich embodiment an antenna portion is positioned inside a sailcloth,

FIG. 7 shows the antenna portion and its damping piece,

FIG. 8 shows another embodiment of the wing sail tip, in whichembodiment the antenna portion is positioned outside the sailcloth and

FIG. 9 shows one embodiment of the wing sail seen in the symmetry plane.

DESCRIPTION OF PREFERRED EMBODIMENTS

In FIG. 1, a wing sail 1 according to the invention is in an operatingposition. From the Figure is seen that the wing sail is gripped withboth hands. In addition, trapezes of different kinds can be used duringsailing.

FIG. 2 shows the wing sail of FIG. 1 from below. The wing sail comprisesa sailcloth 2 or the like, mast tubes 3a and 3b, which are positioned ina V shape, situated in sailcloth pockets and define a nose angle α, aboom 4 located symmetrically between the mast tubes, a traverse tube 5,supporting tubes 6a and 6b, antenna portions 7a and 7b with theirtightening means 8a, 8b, a nose link 9, a branch member 10 and sailbattens 11a, 11b, 12a, 12b and 13. The boom 4 is curved in the areabetween the branch member 10 and the nose link 9 so that its maximumdistance X from the sailcloth 2 is 25 to 50 cm at the symmetry plane.The branch member 10 is situated at the maximum distance or close tothat. In the example of the figure, the distance between the branchmember 10 and the nose link 9 is about 30% of the boom 4 length. Theboom 4 is substantially straight from the branch member 10 backwards.

FIG. 3 shows the wing sail folded for transport. The mast tubes 3a and3b are brought near the boom 4 and the sailcloth 2 is slackened. It isnot necessary to detach the sailcloth 2 from the mast tubes 3a and 3bwhen the wing sail is mounted to a foldable position. The nose link 9ties together the mast tubes 3a and 3b of the wing sail provided withthe sailcloth 2 and the boom 4. The nose link 9 makes it possible tochange the nose angle α and to fold the mast tubes 3a, 3b with respectto the boom 4, for mounting the wing sail into a sailing position and afolded position for transport, respectively. The supporting tubes 6a,6b, the traverse tube 5 and the sail battens 11a, 11b, 12a, 12b and 13of the wing sail are illustrated ready for transport beside thesailcloth 2. During transport, a preferred embodiment of the wing sailthus comprises nine separate structural parts.

From the components shown in FIG. 3, wing halves 2a, 2b of the wing sail1 are initially opened for mounting the wing sail 1 into working order,by moving tips 14a, 14b of the mast tubes 3a and 3b farther away fromeach other. Subsequently, a traverse tube 5 is mounted between the masttubes 3a and 3b. The traverse tube 5, fastened to connection pieces 15aand 15b at the mast tubes 3a, 3b, keeps the mast tubes and the winghalves 2a, 2b separate from each other. The distance between theconnection pieces 15a, 15b and the nose link 9 is 30 to 60% of thelength of the mast tubes 3a, 3b. Said area provides a firm and durableand, at the same time, light construction and makes a good aerodynamicspossible. In case of FIG. 2, the distance is about 50%. By utilizing thetightening means 8a and 8b (see FIGS. 2 and 6) at the tips of theantenna portions 7a and 7b, the sailcloth 2 is pulled taut. Then theantenna portions 7a and 7b are stretched to form a bow, because they aremade of a flexible material. During stretching, the traverse tube 5 isalso locked to the connection pieces 15a, 15b. The tightening means 8a,8b comprise a string 16a, 16b and a stay tightener 17a, 17b, consistingfor instance of a tapering link, to which the string is stretched. Sincethe antenna portions 7a, 7b are mounted within pockets 18a of thesailcloth, tips 19a, 19b of the sailcloth 2 are provided with a curvedshape. While the rear end of the boom 4 is lifted slightly upwards fromthe remaining sail construction, ends of the supporting tubes 6a and 6bare mounted in place to their own connection means 20a and 20b. Thedistance between the connection means 20a, 20b and the nose link 9 is 20to 40% of the length of the mast tube 3a, 3b and the distance betweenthe branch member 10 and the nose link 9 is 20 to 50% of the boom 4length. Said areas provide a firm and light construction and acapability of self-stretching and an easy-sailed wing sail, wherebyplaces for the hands (handles 35a and 35b) are situated symmetrically onboth sides of the aerodynamic midpoint. In case of FIG. 2, saiddistances are about 30%. The branch member 10 situated on the front halfof the boom 4 is meant for receiving the opposite ends of the supportingtubes 6a and 6b. The branch member 10 enclosing the boom 4 like a sleevecomprises two Y-shaped portions 10a, 10b, which are formed integrallyfastened to each other, see FIG. 4. The connection described is rigidand maintains the rigidity of the construction. The supporting tubes 6a,6b lock the mast tubes 3a, 3b rigidly to the boom 4 and maintain theshape of the wing sail 2.

The final shape of the wing sail is provided after the mounting of thesail battens 11a, 11b, 12a, 12b and 13 by stretching the sailcloth 2 attensioning means 21a and 21b situated at the rear end of the boom 4towards the rear portion of the boom 4. Then the ends of the supportingtubes 6a, 6b are also locked to the connection means 20a, 20b and thebranch member 10. The sail batten 13 and the boom 4 define the symmetryplane of the wing sail. From FIG. 2 is seen that the traverse tube 5 issituated between the sail batten 13 and the boom 4 in such a way thatthe sail batten 13 exposes the midpoint of the traverse tube 5 to aforce. All sail battens 11a, 11b, 12a, 12b and 13 comprise tensioningmeans, cf. FIG. 6, from which is seen that the sail batten 11a, forinstance, comprises tensioning means 22a.

From the above is understood that the wing sail 1 constitutes aself-stretching, shape permanent, light kite rig suitably self-adjustingduring sailing, in which rig the wing halves 2a, 2b form a slight Vangle when the wing sail is looked at straight from the front. The noseangle α is then preferably 120° to 140°. If the nose angle α exceeds140°, the sailability of the wing sail suffers essentially. Theconstruction is symmetric with respect to the symmetry plane of the wingsail. In FIG. 1, the boom 4 and the midmost sail batten 13 are situatedin the symmetry plane. Thanks to the capability of self-stretching, thesupporting tubes 6a, 6b and the traverse tube 5 do not require separatelocking means. Instead, the firmer said tubes are locked to the masttubes and the boom, the firmer the tension is at the tightening means8a, 8b of the antenna portions and at the tensioning means 21a, 21b inthe rear of the boom 4.

As appears from FIG. 4, the branch member 10 is displaceable in thelongitudinal direction of the boom 4. By means of tenon and mortisejoint means 23, 24, the branch member can be locked to a desired placeof the boom 4.

The connection means 20a, 20b and the connection pieces 15a, 15bcomprise a sleeve portion 25a, 26a (25b and 26b are seen from FIG. 2)enclosing the mast tubes 3a, 3b, to which sleeve portion are arranged bymeans of a bolted joint 27a, 28a receiving pieces 29a, 30a for receivingthe supporting tubes 6a, 6b and the traverse tube 5, respectively.

The traverse tube 5 includes an adjuster sleeve 31, which comprises atenon and mortise joint 32, 33 for adjusting the length of the traversetube and the nose angle α between the mast tubes 3a, 3b. The adjustersleeve 31 can be locked to different points of the traverse tube 5 bymeans of the tenon and mortise joint 32, 33. Since the traverse tube 5comprises said adjusting/locking means, it is recommendable that thesupporting tubes 3a, 3b also comprise adjusting/locking means foradjusting their length. The adjusting means of the supporting tubes 3a,3b can be of tenon and mortise joint type.

To facilitate sailing, the front part of the wing sail 2 preferablycomprises a transparent area in the range of the traverse tube 5.

In FIGS. 1 and 2, reference numerals 34, 35a, 35b indicate handles tohold on during sailing. The handle 34 is situated in the middle or rearpart of the boom and the handles 35a, 35b are situated at the boom 4 endof the supporting tubes 6a, 6b. The handle 34 and, subject to on whichside of the wing sail 1 the sailer is, either the handle 35a or 35b areheld simultaneously. The distance Y between the handle 34 and thesailcloth 2 is 15 to 25 cm, preferably 17 to 20 cm. The sailer can meetthe wind even at an angle of 40°, all angles exceeding said angle beingpossible during sailing. A tack is changed by rising on the skisstraight towards the wind, while the wing sail is lifted above the headand flies exactly in the horizontal plane, and by falling on the skis tothe other tack, whereby the wing sail is lowered down to the normaloblique position again. At a tack change, the hand holding the handle ofa supporting tube is moved to hold the boom handle, and the hand holdingthe boom handle is moved to hold the handle of the other supportingtube.

The structure of the nose link 9 appears from FIG. 4 in more detail. Thenose link 9 comprises plugs 36a and 36b mounted inside the mast tubes 3aand 3b, through which plugs is inserted a flexible threadlike material37, which is substantially inextensible in the longitudinal directionand joins the mast tubes 3a and 3b together. The threadlike material 37is locked to the plugs 36a, 36b by means of a knot, for instance. Theboom 4 is suspended from the threadlike material 37 by providing asleeve 38 at the nose of the boom with a hole in the transversedirection. The threadlike material 37 makes it possible to turn the masttubes 3a, 3b and the boom 4 freely with respect to each other. Theconnection manner described makes it possible to join the mast tubes 3aand 3b and the boom 4 as well as the sail-cloth 2 to a tight bundle fortransport without detaching the sail-cloth from the mast tubes 3a, 3b.The portions 3a and 3b as well as 4 may be moved with respect to eachother when the construction is free and without tension. The threadmaterial 37 of the nose link 9 is stretched taut and keeps the wing sail1 together when stretched ready for sailing. The described threadlikenose link 9 is very light, firm and solid and, in addition to that, easyto provide.

FIG. 5 shows one way of fixing a traverse tube 5' to a mast tube 3a'. Aconnection piece 26a' encloses the mast tube 3a' and the connectionpiece comprises a tenon part 30a', on which the end of the traverse tube5' is pushed. Reference numeral 28a' indicates the location of a link,which comprises a fixing screw. Connection means for fixing thesupporting tubes may preferably be according to FIG. 5.

FIG. 6 shows the tip of a wing sail, in which the antenna portion 7a isdetachably fixed to the ends 14a of the mast tubes 3a, 3b in such a waythat the antenna portion is situated inside a sail pocket 18a at a frontedge 39 of the sailcloth 2. Reference numeral 40a indicates a curvedseam. When the sailcloth 2 is stretched by the tightening means 8asituated at the tip part of the antenna portion 7a, the sailcloth 2 isstretched into its shape. Then the antenna portion 7a forms togetherwith the sailcloth 2 a curved shape along a portion between the tip 14aof the mast tube 3a and the tip 41a of the antenna portion 7a attachedthereto. This curvature keeps its shape during sailing by means of thetension caused by the tightening means 8a. When the tension is loosened,the antenna portion 7a will be straight due to its flexibility, asappears from the FIGS. 3 and 7.

The antenna portions 7a and 7b may be made of different elasticmaterials and be profiles having cross-sections of different shapes. Thecross-section is preferably such that the antenna portion yields in apredetermined bending direction, but is substantially rigid in anotherbending direction perpendicular with respect to the first-mentioneddirection. The shape of the cross-section may preferably be essentiallyflat; a semicircle or a rectangle. Such properties are provided by meansof a flat profile material. The antenna portions 7a, 7b may be fixeddetachably to the mast tubes 3a, 3b in various positions. This makes itpossible to change the antenna portions as well as to change the angleof attack between the tip 19a of the sailcloth 2 and the wind forfinding an optimal sail geometry.

The wing sail according to the invention, provided with a standardsailcloth of 4.3 square meters, weighs only 5 to 6 kg, the frame membersof the rig being made of a firm aluminium alloy and/or glass fibre tube.Lightness is of primary importance for a self-supported wing sail.

FIG. 7 shows the antenna portion 7a in a state without tension, wherebyit is straight. The end of the antenna portion is provided with aflexible damping piece 42a, which yields, when loaded, by bending easierthan the antenna portion 7a. The damping piece 42a serving as a bufferefficiently prevents the tip of the wing sail from being broken, in casethe tip meets an obstacle. At the same time, the damping piece 42a makesthe use of the wing sail safe.

FIG. 8 shows an alternative wing sail tip 19a". A sailcloth 2" is fixedto a mast tube 3a" in such a way that an antenna portion 7a" remainsoutside the sailcloth. The sailcloth 2" is at its tip tied to theantenna portion 7a" (like in Figure) or alternatively to a tip 14a" ofthe mast tube 3a. Different sail cuttings are made possible in this way.The antenna portions 7a" and 7b" described in this embodiment can alsobe detached and mounted at the tip 14a" of the mast tube 3a" indifferent positions and at different angles.

FIG. 9 illustrates an embodiment of the wing sail, comprising a lowersailcloth 43'". The lower sailcloth 43'" is arranged in the area betweena sailcloth 2'" and a boom 4'" and extends between the mast tubes and isstretched straight up to a rear edge 44'" of the sailcloth. Such a wingsail is somewhat quicker than the solution in which there is no lowersailcloth 43'", because the induced resistance of the wing is smaller.

The use of the described wing sail is not restricted to winter sailingonly, but it may also be used on roller skis and skates, for instance.The invention and its embodiments are not limited to the embodiments setforth in the specification and drawings, but the details of theinvention may be implemented in many ways within the scope of theattached claims. Accordingly, it is not necessary that the branch memberis displaceable in the boom direction and the length of the traversetube and supporting tubes can be adjusted. Differing from the above,length adjustment--if there is one--may be implemented by usingtelescope tubes. Instead of a branch member, a connection member ofanother type may be used.

We claim:
 1. A handheld wing sail comprising:a sailcloth (2) supportedon frame members (3a, 3b, 4, 5, 6a, 6b, 7a, 7b), the frame memberscomprising two mast tubes (3a and 3b) positioned in a V shape defining anose angle (α) and opposite respective tips (14a), a boom (4) located inthe area between the mast tubes, the boom being curved at the symmetryplane of the wing sail and connected to each mast tube (3a and 3b) bysupporting tubes (6a, 6b), which are at one end fastened to the boom (4)by a connection member (10) and at the opposite end to the respectivemast tubes (3a and 3b) by connection means (20a, 20b), and a traversetube (5) joining the mast tubes (3a, 3b) together and fastened to themast tubes by connection pieces (15a, 15b), wherein the mast tubes (3a,3b) and the boom (4) are connected to each other by a nose link (9),which comprises a threadlike connection member (37), which is made offlexible but substantially non-stretchable material for making itpossible to change the nose angel (α) and to fold the mast tubes (3a,3b) toward the boom (4), whereby to bring the wing sail into a foldedposition for turning the mast tubes (3a, 3b) and the boom (4) freely indifferent directions when the wing sail is in the folded position and,thus, ready for transport, the tips (14a) of the mast tubes (3a, 3b)have, at tips (19a, 19b) of the sailcloth (2), flexible antenna portions(7a, 7b) to which are connected tightening means (8a, 8b) for keepingthe wing sail taut during sailing, the boom (4) is curved in such a waythat its maximum distance (X) from the sailcloth (2) is 25 to 50 cm atthe symmetry plane of the wing sail, and the distance between theconnection member (10) and the nose link (9) is 20 to 50% of the boom(4) length.
 2. A wing sail according to claim 1, wherein the distancebetween the connection means (20a, 20b) and the nose link (9) is 20 to40% of the length of the mast tubes (3a, 3b) and that the distancebetween the connection pieces (15a, 15b) and the nose link (9) is 30 to60% of the length of the mast tubes (3a, 3b).
 3. A wing sail accordingto claim 1, wherein the sailcloth (2) is fastened to the antennaportions (7a, 7b) to provide the tips (19a, 19b) of the sailcloth (2)with a curved shape.
 4. A wing sail according to claim 3, wherein theantenna portions (7a, 7b) are fastened to the tips (14a) of the masttubes (3a, 3b) in such a way that they are situated inside the sailcloth(2).
 5. A wing sail according to claim 1, wherein the antenna portions(7a, 7b) are fastened to the tips (14a) of the mast tubes (3a, 3b) insuch a way that they are situated inside the sailcloth (2).
 6. A wingsail according to claim 5, wherein the antenna portions (7a, 7b) arefastened detachably to the tips (14a) of the mast tubes (3a, 3b).
 7. Awing sail according to claim 1, wherein the antenna portions (7a, 7b)are manufactured of a profile material that yields in a predeterminedbending direction, but is substantially rigid in another bendingdirection.
 8. A wing sail according to claim 1, wherein the free ends ofthe antenna portions (7a, 7b) are provided with a flexible damping piece(42a, 42b) for lifting up the tips (19a, 19b) of the sailcloth (2) whenthe tips of the sailcloth meet an obstacle.
 9. A wing sail according toclaim 1, comprising sail battens (11a, 11b, 12a, 12b and 13), one (13)of which is situated at least approximately in the symmetry plane of thewing sail, wherein the traverse tube (5) is situated between the sailbatten (13) situated at least approximately in the symmetry plane of thewing sail (2) and the boom (4) in such a way that the sail battenexposes the transverse tube (5) to a force.
 10. A wing sail according toclaim 1, wherein the connection member consists of a branch member (10),which is made of a stiff material, encloses the boom (4) and comprisestwo Y-shaped pieces (10a and 10b) connecting the supporting tubes (6a,6b) rigidly to each other.
 11. A wing sail according to claim 10,wherein the branch member (10) is displaceable in the longitudinaldirection of the boom (4) and lockable to at least two places of theboom by means of locking means (23, 24).
 12. A wing sail according toclaim 11, wherein the locking means are of tenon and mortise joint (23,24) type.
 13. A wing sail according to claim 1, wherein the connectionmeans (20a, 20b) and the connection members (15a, 15b) comprise a sleeveportion (25a, 25b, 26a, 26b) enclosing the mast tubes (3a, 3b), to whichsleeve portion, by means of a bolted joint (27a, 28a), receiving pieces(29a, 30a) are arranged for receiving the supporting tubes (6a, 6b) andthe traverse tube (5), respectively.
 14. A wing sail according to claim1, wherein the traverse tube (5) comprises adjusting means (31 to 33)for adjusting its length and the nose angle (α) between the mast tubes(3a, 3b).
 15. A wing sail according to claim 14, wherein the adjustingmeans consist of an adjuster sleeve (31) arranged in the traverse tubeand lockable to different places of the traverse tube by means of atenon and mortise joint (32, 33).
 16. A wing sail according to claim 14,wherein the supporting tubes (6a, 6b) comprise adjusting means foradjusting their length.
 17. A wing sail according to claim 1, andfurther comprising a lower sailcloth (43'") in an area between thesailcloth (2'") and the boom (4'").